Pokémon Red and Blue

This page contains notes for the game Pokémon Red and Blue.

The following tables were created with the help of the documentation provided by the Pokémon Red Disassembly Project.

Unused Song#

This unused song is simply known as Koukan, which translates to “Trading”. In source/MUSHEAD.DMG, the song's headers are placed after the "follow-me" song (called musautowalk). Unusually, this song is split into two headers, each pointing at different channel data. They are both commented out, and would've had the labels muskoukan1 and muskoukan2.

The usual sound header format in the Pokémon games goes like this: take a four-channel track, for example: C0 xx xx 01 xx xx 02 xx xx 03 xx xx. From left to right, the sound engine will read these series of bytes as follows:

1. Read byte 0xC0 hexadecimal. This encodes the total number of channels as well as which channel should the following pointer be assigned to. The total number of channels are encoded in bits 6–7, which in this case is %11 binary. Throughout this header, a value of 0 is interpreted as 1. So, despite ordinarily meaning 3 in decimal, this actually means 4, therefore the sound has 4 channels. Bits 0–3 encode which channel the following pointer is assigned to, which follows the same convention. Here, it's %00, which means the first Game Boy channel.
2. Read 2 bytes xx xx. The preceding byte says this is to be assigned to channel 1, so this is the pointer that contains the data played on channel 1.
3. We still have 3 more channels to go, so read another byte 0x01. Using the same interpretation as in step 1, this means that we assign the following pointer of 1 channel to channel 2.
4. Read 2 bytes xx xx. The preceding byte says this is to be assigned to channel 2, so this is the pointer that contains the data played on channel 2.
5. Repeat steps 3 and 4 two more times to cover channels 3 and 4.

The channel assignment numbers start from 0 for music and 4 for sound effects—in which case, giving us four “virtual SFX channels” in channels 5, 6, 7, and 8.

Koukan’s headers both look like this: 02 xx xx. Using the same interpretation rules, this gives both of its parts a header meaning “data for 1 channel to be played through channel 3”.

While the headers were never compiled in the retail ROM, the data itself is, so we can use audio/music/unusedsong.asm from the Pokémon Red & Blue disassembly to help explain things:

• Both channel data has a tempo 144 command listed. Usually, the tempo command is required only in the first channel of a music track. However, because each “channel” actually belongs to two separate headers, the tempo must be defined separately in both channel data as well.
• Both channel data lists the command note_type 12, 1, 0. In the context of channels 1 and 2 (square wave channels), this command doesn't make much sense: it specifies a note type of length 12, volume 1 and 0 fade. A volume of 1 here is the lowest possible volume, and is likely the reason why the “damaged” version sounds quiet. On the other hand, in the context of channel 3 (the wave channel), this command specifies a note type of length 12, volume 1, and wave instrument 0. Here, a volume of 1 encodes the highest possible volume for the wave channel.
• There are no duty cycle commands or anything else that would make sense for a square wave channel.

Taking into consideration the arrangement of the song header as well as the song data above, it can be assumed that the song was likely meant to be played using two Game Boys. There may have been technical reasons why it was scrapped: if one were to speculate, synchronization problems might have been a factor.

It may be also worth noting the source version, KOUKAN.MUS, assigns the channel data to channels 2 and 3, while channels 1 and 4 are all rests. Given the information above, this is likely for ease of composition. In the G/S sources, a version of this file converted into the G/S/C sound commands is mons2/SOURCE/EFFDATA/M_TRADE.DAT, further confirming the song's original purpose.

Additionally, the notes may have been pitched one octave too high. The other unused R/G/B songs that were discovered in the G/S source but were unused seem to have also been pitched too high, if the restorations tell us anything. This could either be as a result of engine changes, or the macros/conversion tooling itself changing.

Base Types#

Each Pokémon's cry is built off a "base" that is shared with other Pokémon, often those within the same evolutionary family. All cries have an internal name defined in MVOICE.H and MVOICE.DAT in the leaked source code (more information here). Not all base cries are actually used in the games. In these cases, a known Pokémon that uses a variation is listed in italics in the table below.

There is also an additional base cry defined in the game that is completely unreferenced anywhere, and not used by any Pokémon. This is named earthtron in the leaked source code, referencing an Ultraman series kaiju, Arstron. Interestingy, this cry would remain in the games all the way until Pokémon Crystal.

Cry Values#

This table lists each cry's base, pitch, and length values in both hexadecimal and decimal.